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What evidence is there for evolution?

For IB Biology, there are three types of evidence for evolution you need to know: fossils, selective breeding and homologous structures. Fossils are preserved remains or traces of organisms from the past – t...
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Answered by Emma F. • Biology tutor
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describe how the plant hormone auxin and light affects the direction of growth of plants

The hormone auxin causes cells in shoots to grow faster, and cells in roots to grow more slowly. Auxin becomes more concentrated on the side of the plant that is not facing the light, the shaded side. In the...
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Answered by Niamh D. • Biology tutor
19460 Views

How is selective reabsorption acheived in the kidneys?

In the cells lining the proximal convoluted tubule, sodium-potassium pumps present in the membrane in contact with tissue fluid pump sodium ions out of the cells. This lowers the concentration of sodium ions...
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Answered by Nianqi S. • Biology tutor
14521 Views

What is diffusion?

By definition, diffusion is the movement of particles from a region of high concentration to a region of low concentration. It occurs in liquids and gases where particles can move freely down a concentration...
ED
Answered by Eleanor D. • Biology tutor
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What is a protein?

A protein is a sequence of many amino acids. All proteins are made of amino acids. Humans have 20 distinguished amino acids that can arrange in thousands of different combinations and this means that they ca...
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Answered by Matilde M. • Biology tutor
3978 Views